Koh Kood is the farthest island from the coast of Trat. Its size ranks as the fourth of all Thailand's islands or the second to Koh Chang in Trat. The island covers an area of approximately 105 sq.km or 65,625 rai. It is 25 km in length and 12 km in width. Its natural features include mountains and plains where many streams originate and some become waterfalls.

One famous waterfall is Nam Tok Khlong Chao flows all throughout the year. It is an ideal place for swimming, consisting of 3 tiers; the upper two tiers are running streams and the lower one is a large pond. In 1911, King Rama VI paid a royal visit to this waterfakk and named it 'Nam Tok Anam Kok' to commemorate Ong Chiang Su. In addition; there are beaches with crystal-clear sea popular among visitors such as Taphao Beach, Khlong Chao Beach, Khlong Hin Beach, Phrao Beach, etc. Accommodation with a private atmosphere is available for visitors at the inner sea of Koh Kood, and the other two islands, Ko Rat and Ko Mai Si, opposite to Koh Kood.

Most visitors to Koh Kood have to purchase a package tour offered by resort operators on Koh Kood at different prices that includes food, accommodation, and a boat fare. A boat for rent is also available apart from a ferry boat leaving Dan Kao Pier and Laem Ngob Pier.